Nesting of multiple broadband services exists in an IP multimedia system (hereafter referred to as IMS), especially when a user subscribes to SIP Terminal call (hereafter referred to as STC) services, such as call hold and call transfer. Terminating call services of that type are processed by a terminating call service server.
For example, in the case of a conference call, a conference service server routes calls of participants A, B, and C, where user B subscribes to a call hold service in terminating call services. When the user B receives another call, user B holds the original call and answers the new incoming call. A terminating call service server of B identifies that B initiates a call hold operation and needs to play a hold tone to a caller leg of B. In a site where B is located, all participants (excluding B) hear the hold tone, which disturbs the normal order of the site.
In another case, a user subscribes to a wake-up call service. At the wake-up time specified by user A, a wake-up call service server delivers a route to a number of user A. In normal conditions, a terminal equipment of user A rings, achieving the purpose of wake-up. In this case, if user A subscribes to a terminating call service and a service such as call forwarding unconditional or one number link you, an incoming wake-up call is transferred to another forwarded-to number, and the purpose of waking up A through an alarm tone cannot be achieved.
The preceding current services (conference call and wake-up call services) cannot be normally performed due to impacts of subsequent terminating call services (call hold and call transfer). Situations where the preceding current services cannot be normally performed due to mutual impacts between the current services and the subsequent terminating call services are collectively referred to as broadband service nesting, and no effective technical solution is provided in the prior art.